What age to grow out of size 1?

My DD was still in size 1 at 13-14 months - we tested the very first Tots Bots in a size 1!

So it varies alot then really!!!
Sophies fit fine round the waist, tonnes of room, only just stopped crossing over thge tabs on the little lambs. Its just the rise is very short!! She does have to have 2 boosetrs in though, that might be why. Even her pockets are bulky from all the boosting
Not sure what to get, i think sz 2 wlll drown her.....

It was ages until Ben grew out of his size 1's but then I can't remember when. I think it was at about 5 to 6 months, around the time he started eating food and out peeing his nappies just before weaning had started. But he was wearing his size 1's folded down to 0's from 6lbs to 7 1/2lbs, so about a month or two.

I was buying large huggles for Isabelle at 7 months (and she was only 4lbs 7 when she was born!!)

Rhys outgrew his around the 3 month mark I'm now starting to suspect that the rise on the size 2's is getting a bit skimpy , means quite a bit more expense than I was planning (having bought what I believed to be a BTP pack ) He's 15 months and about 25ish lb.

My skinny boy's still in his size 1s! The tots are almost too small, but only from a builders bum perspective, they're still fine around the waist. And his little lambs are still fine all over. To think I was worried about buying too many size 1s in case I didn't need them for long

He can wear size 2 bamboozles too, although I prefer the trim look of the size 1s so am in no rush to move up to the next size.